Abstract: Aggregated crystalline silicon powder with a BET surface area of 20 to 150 m2/g. It is prepared by subjecting at least one vaporous or gaseous silane and optionally at least one vaporous or gaseous doping material, an inert gas and hydrogen to heat in a hot wall reactor, cooling the reaction mixture or allowing the reaction mixture to cool and separating the product from gaseous substances in the form of a powder, wherein the proportion of silane is between 0.1 and 90 wt.%, with respect to the sum of silane, doping material, hydrogen and inert gases, and wherein the proportion of hydrogen, with respect to the sum of hydrogen, silane, inert gas and doping material, is in the range 1 mol. % to 96 mol. %. It can be used to produce electronic components.